Sodium Hypo FRP - CRECO, Inc.

SECTION { }
FIBERGLASS REINFORCED PLASTIC TANKS
PART 1 - GENERAL
1.1 SCOPE OF WORK
A. This section covers the furnishing and installation of fiberglass reinforced plastic tanks
for the storage of Sodium Hypochlorite.
Connecting piping, valves and accessories not specified herein are covered in other
sections.
1.2 SUBMITTALS
A. Submit to the Engineer, in accordance with the submittal section, complete drawings,
details, and specifications covering tanks, fittings and accessories.
B. Drawing Approval
1. Shop drawings shall be approved by the Engineer prior to fabrication. Approval of
Drawings by the Engineer shall not release the Contractor of responsibility of
compliance with this Section. All proposed changes to this Section shall be stated
in writing.
1.3 REFERENCE STANDARDS
A. All materials and construction methods shall comply with the applicable provisions of
the following standards:
1. ASTM D-3299-00 - Standard Specification for Filament-Wound Glass-Fiber-
Reinforced Thermoset Resin Corrosion-Resistant Tanks.
2. ASTM D-4097-00 - Standard Specification for Contact-Molded Glass-Fiber-
Reinforced Thermoset Resin Corrosion-Resistant Tanks.
3. ASTM D-2563 - Standard Practice for Classifying Defects in Glass-Reinforced
Plastic Laminate Parts.
4. Where applicable, provision from A.N.S.I./A.W.W.A. D120-84 – Thermoset
Fiberglass Reinforced Plastic Tanks and A.S.M.E./A.N.S.I. RTP-1-1995 –
Reinforced Thermoset Plastic Corrosion Resistant Equipment will be used.
B. Occupational Safety and Health Administration (OSHA)
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1.4 DESCRIPTION OF TERMS
A. Definitions for most terms used within this standard are in accordance with ASTM
D-883 Definitions of terms relating to plastics.
B. FILAMENT WOUND – The process in which the principle circumferential load bearing
reinforcement is applied by continuous filament winding.
C. CONTACT MOLDED – A molding process that includes spray-up, hand lay-up, or a
combination of those manufacturing processes.
D. HEAD – The end closure of cylindrical tanks (top or bottom).
1.5 DELIVERY, STORAGE AND HANDLING
A. Delivery, storage and handling of the fiberglass tanks shall be in accordance with the
tank manufacturers Handling & Installation Instructions.
B. The Contractor shall require the manufacturer to assume responsibility for packaging to
prevent normal transit and handling damage to the tanks.
C. Flange faces shall be protected from damage. All openings are to be securely covered to
prevent entrance of dirt, water and debris.
D. Tanks shall be mounted on skids or protective framework so constructed as to provide
for easy handling for fork truck or similar device or be provided with lifting lugs, to
permit handling by crane. Nozzles, manholes, or other fittings shall not be used for
lifting.
PART 2 - PRODUCTS
2.1 GENERAL
Designation
Classification
Number of tanks
Useable capacity,
measured to invert of
overflow connection,
gallons each
Diameter, feet
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Chemical
Specific Gravity
Maximum Operating
Temperature
Location (Indoor /
Outdoor)
Top (Open, Open
w/Cover, Dome, Flat)
Bottom (Flat, Sloped,
Dished, Cone)
2.2 ACCEPTABLE MANUFACTURERS
A. Tanks shall be constructed by a firm that has at least ten years prior experience in
construction of similar fiberglass tanks.
B. The fiberglass tanks shall be as supplied by CRECO, Incorporated, Crete, IL.
2.3 MATERIALS
A. RESIN – The resins used shall be a corrosion resistant vinylester thermoset resin that
has been determined by previous documented service to be acceptable for the particular
service conditions. Catalyst system shall be BPO/DMA catalyst. The resin shall
contain no pigments, colorants, or fillers unless specified by the customer.
B. SURFACING VEIL – The inner surface reinforcement shall consist of a double nexus
surfacing veil. The surfacing veil shall contain a coupling agent or binder that is
compatible with the corrosion barrier resin.
C. CHOPPED STRAND MAT OR GUN APPLIED CHOPPED STRANDS – shall be
constructed from single-end type E-glass strands 1/2” minimum to 2” maximum length.
The coupling agent or binder shall be compatible with the resin used.
D. CONTINUOUS ROVING – Filament winding requires a single-end type E-glass
reinforcement with 250 yards/pound yield. The coupling agent or binder shall be
compatible with the resin used.
E. WOVEN ROVING – Shall be minimum 18 ounces/square yard and compatible with the
resin used.
2.4 LAMINATE CONSTRUCTION
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A. STRUCTURAL TANK – The laminate comprising the structural tank (bottom head,
sidewall, and top head) shall consist of three separate laminates. These are the inner
surface and the interior layer, which make up the corrosion barrier, and the structural
layer.
B. INNER SURFACE – The inner surface exposed to the chemical environment shall be a
resin rich layer .010 to .020 inch thick, reinforced with a double nexus synthetic
surfacing veil. The glass content shall be 10% by weight maximum in this layer.
C. INTERIOR LAYER – The interior layer shall consist of a resin rich laminate reinforced
with chopped strands. The glass content shall be 27% +/- 5% by weight. The combined
thickness of the inner surface and the interior layer shall not be less than .100 inch.
D. STRUCTURAL LAYER
1. FILAMENT WOUND STRUCTURAL LAYER – Subsequent reinforcement shall
be continuous strand roving. Glass content of the filament wound structural layer
shall be 60% to 70% by weight. The thickness of the filament wound portion of the
tank shell will vary with tank height (tapered wall construction). If additional axial
strength is required, the use of chopped strands or unidirectional glass strands
interspersed between wind layers is acceptable.
2. CONTACT MOLDED STRUCTURAL LAYER – Subsequent reinforcement shall
be comprised of alternating layers of chopped strands and such additional number
of plies of woven roving to a thickness as required to meet the physical properties
that are used for the design. Each successive ply or pass of reinforcement shall be
well rolled prior to the application of additional reinforcement. All woven shall be
overlapped 1”. Laps in subsequent layers shall be staggered at least 3” from laps in
the preceding layer. The final outer layer shall be chopped strands in all cases.
E. JOINTS – Joints between sidewall sections, and for attachment of top heads or bottom
heads shall conform to the width and thickness as specified in the applicable standards.
F. The outer surface shall be coated with a 10 mil. thick layer of resin for spill protection.
This layer will also contain ultraviolet absorbers and white gelcoat.
G. Where air inhibited resin is exposed to air during cure, a full surface cure shall be
obtained by coating the surface with a coat of resin containing 0.2% to 0.6% paraffin
wax surfacing agent. Tank shall also undergo a minimum four hour post heat cure for
sodium hypochlorite service.
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2.5 MANHOLES, FITTINGS AND ACCESSORIES
A. TOP AND SIDE MANWAYS – Shall be constructed using hand lay-up construction,
and of the same materials as the tank they are installed in. Pre-fabricated press molded
flat plate side manhole covers are not acceptable.
B. FLANGED NOZZLES – The nozzle shall be of hand lay-up construction. Press molded
flanges attached to pipe with adhesive are not acceptable, except for the inner flange on
a double flange nozzle.
C. COUPLINGS, NIPPLES, PIPE STUBS – Shall be of filament wound or contact molded
construction. Press molded fittings are not acceptable.
Tanks shall be provided with the following flanged nozzles:
Quantity
Connection
Nozzle Size in Inches
Location
on Tank
Tank shall be provided with the following accessories:
Quantity Description Location on Tank
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D. VENTS – Unless agreed upon in advance by CRECO, Inc. all tanks shall be vented to
prevent an internal pressure or vacuum. The vent must be of sufficient size to handle the
flow displacement of all combined inlet or outlet nozzles.
NOTE: Tanks are not designed for improper Air Loading.
E. LIFTING LUGS – Shall be installed on tanks weighing over 200 pounds, unless
otherwise specified.
F. HOLD DOWN LUGS – The size and number of hold down lugs shall depend on the
wind, seismic, and other loads the tank will be subjected to during normal operation.
G. NAMEPLATE:
Tank nameplate shall be constructed of FRP materials and located approximately 5’ up
from tank bottom where possible. The nameplate shall include the following
information:
1. Serial number 8. Service temperature
2. Customer 9. Product
3. Customer purchase order number 10. Corrosion barrier veil
4. Tank model 11. Corrosion barrier resin
5. Tank capacity 12. Structural layer resin
6. Design pressure 13. Date of fabrication
7. Specific Gravity 14. Tank tag (If Specified by Customer)
PART 3 - EXECUTION
3.1 INSTALLATION
A. Install the fiberglass tanks in accordance with the drawings, the manufacturer’s
installation instructions and to the satisfaction of the Engineer.
B. Tanks shall be installed on a minimum of 2 layers of 30-lb. roofing felt, or other
resilient support, on a level, smooth troweled concrete pad.
3.2 TESTING
A. After installation and inspection, each tank shall be field tested by filling to the overflow
with water. The tank and fittings shall hold water without loss or evidence of weeping
for a period of 24 hours.
B. After testing, the tanks shall be drained, thoroughly, cleaned and dried.
C. Should any defects in workmanship or materials become evident during inspection,
testing, or within the warranty period, repair or replace the defective tank or fitting as
approved by the Engineer at no cost to the Owner.
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